Hepatopancreas

Last updated
Haliotis asinina anatomy.jpg
Photo of a 5-mm-long juvenile of Haliotis asinina (with the shell removed) shows the yellow hepatopancreas on the left.
Haliotis asinina anatomy 3.png
Drawing shows that the mantle (in grey) covers the majority of the dorsal surface of the animal. [1] The gills (g), digestive gland (dg), adductor muscle (am), epipodial tentacles (ept), right mantle lobe (rml), eyespot (es), cephalic tentacles (ct) and left mantle lobe (lml) are indicated.

The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive enzymes, and absorption of digested food. [2]

Contents

Arthropods

Arthropods, especially detritivores in the Order Isopoda, Suborder Oniscidea (woodlice), have been shown to be able to store heavy metals in their hepatopancreas. [3] This could lead to bioaccumulation through the food chain and implications for food web destruction, if the accumulation gets high enough in polluted areas; for example, high metal concentrations are seen in spiders of the genus Dysdera which feed on woodlice, including their hepatopancreas, the major metal storage organ of isopods in polluted sites. [4]

Molluscs

Pseudunela cornuta 2.jpg
3D reconstruction of the general anatomy of Pseudunela cornuta shows the digestive gland (dg) in green color
Pseudunela cornuta 5.png
3D reconstruction of the digestive system of Pseudunela cornuta shows the digestive gland (dg) more clearly
Deroceras laeve hepatopancreas 400 saturn.jpg
Histology section of hepatopancreas of slug Deroceras laeve
Dorsal view of an anesthetized individual of Plakobranchus ocellatus with spread parapodia. Stomach and branched parapodial digestive glands are visible. The tissue region in the red square was dissected and used for DNA extraction in the study by Maeda T. et al. (2012). Plakobranchus ocellatus 4.png
Dorsal view of an anesthetized individual of Plakobranchus ocellatus with spread parapodia. Stomach and branched parapodial digestive glands are visible. The tissue region in the red square was dissected and used for DNA extraction in the study by Maeda T. et al. (2012).

The hepatopancreas is a centre for lipid metabolism and for storage of lipids in gastropods. [6]

Some species in the genus Phyllodesmium contains active zooxanthellae of the genus Symbiodinium in the hepatopancreas. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Onychophora</span> Phylum of invertebrate animals

Onychophora, commonly known as velvet worms or more ambiguously as peripatus, is a phylum of elongate, soft-bodied, many-legged animals. In appearance they have variously been compared to worms with legs, caterpillars, and slugs. They prey upon other invertebrates, which they catch by ejecting an adhesive slime. Approximately 200 species of velvet worms have been described, although the true number of species is likely greater. The two extant families of velvet worms are Peripatidae and Peripatopsidae. They show a peculiar distribution, with the peripatids being predominantly equatorial and tropical, while the peripatopsids are all found south of the equator. It is the only phylum within Animalia that is wholly endemic to terrestrial environments, at least among extant members. Velvet worms are generally considered close relatives of the Arthropoda and Tardigrada, with which they form the proposed taxon Panarthropoda. This makes them of palaeontological interest, as they can help reconstruct the ancestral arthropod. Only two fossil species are confidently assigned to as onychophorans: Antennipatus from the Late Carboniferous, and Cretoperipatus from the Late Cretaceous, the latter belonging to Peripatidae. In modern zoology, they are particularly renowned for their curious mating behaviours and the bearing of live young in some species.

<span class="mw-page-title-main">Chelicerata</span> Subphylum of arthropods

The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda. Chelicerates include the sea spiders, horseshoe crabs, and arachnids, as well as a number of extinct lineages, such as the eurypterids and chasmataspidids.

<span class="mw-page-title-main">Arachnid</span> Class of arthropods

Arachnids are arthropods in the class Arachnida of the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons.

<span class="mw-page-title-main">Chelicerae</span> Mouthparts of spiders and horseshoe crabs

The chelicerae are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or as a type of pincers. Some chelicerae, such as those found on nearly all spiders, are hollow and contain venom glands, used to inject venom into prey or a perceived threat. Both pseudoscorpions and harvestmen have additional structures on their chelicerae that are used for grooming. In Paratrechalea, males and females have shown to have a chelicerae dimorphism, because the chelicerae is used as a mating signal for females.

<span class="mw-page-title-main">Autotomy</span> Self-amputation

Autotomy or 'self-amputation', is the behaviour whereby an animal sheds or discards an appendage, usually as a self-defense mechanism to elude a predator's grasp or to distract the predator and thereby allow escape. Some animals are able to regenerate the lost body part later. Autotomy is thought to have evolved independently at least nine times. The term was coined in 1883 by Leon Fredericq.

<span class="mw-page-title-main">Woodlouse spider</span> Species of spider

The woodlouse spider is a species of spider that preys primarily upon woodlice. Other common names refer to variations on the common name of its prey, including woodlouse hunter, sowbug hunter, sowbug killer, pillbug hunter and slater spider.

<i>Kiwa</i> (crustacean) Genus of crustaceans

Kiwa is a genus of marine decapods living at deep-sea hydrothermal vents and cold seeps. The animals are commonly referred to as "yeti lobsters" or "yeti crabs”, after the legendary yeti, because of their "hairy" or bristly appearance. The genus is placed in its own family, Kiwaidae, in the superfamily Chirostyloidea. The genus Kiwa is named after the god of shellfish in Polynesian mythology.

<span class="mw-page-title-main">Terrestrial animal</span> Animals living on land

Terrestrial animals are animals that live predominantly or entirely on land, as compared with aquatic animals, which live predominantly or entirely in the water, and semiaquatic animals, which rely on both aquatic and terrestrial habitats. Some groups of insects are terrestrial, such as ants, butterflies, earwigs, cockroaches, grasshoppers and many others, while other groups are partially aquatic, such as mosquitoes and dragonflies, which pass their larval stages in water.

<span class="mw-page-title-main">Spider anatomy</span> Physiology of Spiders (order Araneae)

The anatomy of spiders includes many characteristics shared with other arachnids. These characteristics include bodies divided into two tagmata, eight jointed legs, no wings or antennae, the presence of chelicerae and pedipalps, simple eyes, and an exoskeleton, which is periodically shed.

<span class="mw-page-title-main">Marine invertebrates</span> Marine animals without a vertebral column

Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some have evolved a shell or a hard exoskeleton. As on land and in the air, marine invertebrates have a large variety of body plans, and have been categorised into over 30 phyla. They make up most of the macroscopic life in the oceans.

<span class="mw-page-title-main">Woodlouse</span> Crustacean from the polyphyletic suborder Oniscidea

Woodlice are terrestrial isopods in the suborder Oniscidea. Their name is derived from being often found in old wood, and from louse, a parasitic insect, although woodlice are neither parasitic nor insects.

<span class="mw-page-title-main">Coconut crab</span> Species of crustacean

The coconut crab is a terrestrial species of giant hermit crab, and is also known as the robber crab or palm thief. It is the largest terrestrial arthropod known, with a weight of up to 4.1 kg (9 lb). The distance from the tip of one leg to the tip of another can be as wide as 1 m. It is found on islands across the Indian and Pacific Oceans, as far east as the Gambier Islands, Pitcairn Islands and Caroline Island and as far west as Zanzibar. While its range broadly shadows the distribution of the coconut palm, the coconut crab has been extirpated from most areas with a significant human population such as mainland Australia and Madagascar.

<span class="mw-page-title-main">Digestive system of gastropods</span>

The digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods as the largest taxonomic class of the mollusca are very diverse: the group includes carnivores, herbivores, scavengers, filter feeders, and even parasites.

<i>Phyllodesmium</i> Genus of gastropods

Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Myrrhinidae.

<span class="mw-page-title-main">Spider</span> Order of arachnids

Spiders are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except Antarctica, and have become established in nearly every land habitat. As of November 2023, 51,673 spider species in 136 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900.

<i>Hemilepistus reaumuri</i> Species of woodlouse

Hemilepistus reaumuri is a species of woodlouse that lives in and around the deserts of North Africa and the Middle East, "the driest habitat conquered by any species of crustacean, not including insects which are now known to be crustaceans pancrustacea". It reaches a length of 22 mm (0.87 in) and a width of up to 12 mm (0.47 in), and has seven pairs of legs which hold its body unusually high off the ground. The species was described in the Description de l'Égypte after the French Campaign in Egypt and Syria of 1798–1801, but was first formally named by Henri Milne-Edwards in 1840 as Porcellio reaumuri. It reached its current scientific name in 1930 after the former subgenus Hemilepistus was raised to the rank of genus.

Phyllodesmium hyalinum is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Facelinidae.

<i>Phyllodesmium jakobsenae</i> Species of gastropod

Phyllodesmium jakobsenae is a species of sea slug, an aolid nudibranch, a marine gastropod mollusk in the family Facelinidae.

<i>Gigantopelta chessoia</i> Species of gastropod

Gigantopelta chessoia is a species of deep sea snail from hydrothermal vents, a marine gastropod mollusk in the family Peltospiridae.

<span class="mw-page-title-main">Crustacean</span> Subphylum of arthropods

Crustaceans are a group of arthropods that are a part of the subphylum Crustacea, a large, diverse group of mainly aquatic arthropods including decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans.

References

  1. Daniel J. Jackson; Carmel McDougall; Kathryn Green; Fiona Simpson; Gert Wörheide; Bernard M Degnan (2006). "A rapidly evolving secretome builds and patterns a sea shell". BMC Biology . 4: 40. doi: 10.1186/1741-7007-4-40 . PMC   1676022 . PMID   17121673.
  2. "Blue Crab Anatomy". Archived from the original on 2019-01-27. Retrieved 2011-05-19.
  3. Claus Svendsen; Graeme Paton; Jason M. Weeks (2002). "Soil biomarkers (invertebrates and microbes) for assessing site toxicity". In G. I. Sunahara; A. Y. Renoux; C. Thellen; C. L. Gaudet; A. Pilon (eds.). Environmental Analysis of Contaminated Sites. John Wiley and Sons. pp. 95–134. ISBN   978-0-471-98669-0.
  4. S. P. Hopkin; M. H. Martin (1985). "Assimilation of zinc, cadmium, lead, copper and iron by the spider Dysdera crocata, a predator of woodlice" (PDF). Bulletin of Environmental Contamination and Toxicology . 34 (2): 183–187. doi:10.1007/bf01609722. PMID   3978257. S2CID   39086273. Archived from the original (PDF) on 2011-07-22.
  5. Maeda T., Hirose E., Chikaraishi Y., Kawato M., Takishita K. et al. (2012). "Algivore or Phototroph? Plakobranchus ocellatus (Gastropoda) Continuously Acquires Kleptoplasts and Nutrition from Multiple Algal Species in Nature". PLoS ONE 7(7): e42024. doi : 10.1371/journal.pone.0042024
  6. Böer M., Graeve M. & Kattner G. (2006). "Exceptional long-term starvation ability and sites of lipid storage of the Arctic pteropod Clione limacina ". Polar Biology30(5): 571-580. doi : 10.1007/s00300-006-0214-6.
  7. Ingo Burghardt; Heike Wägele (2004). "A new solar powered species of the genus Phyllodesmium Ehrenberg, 1831 (Mollusca: Nudibranchia: Aeolidoidea) from Indonesia with analysis of its photosynthetic activity and notes on biology" (PDF). Zootaxa . 596: 1–18. doi:10.11646/zootaxa.596.1.1.